Tomcat异常讲解

1 Tomcat异常

1 Tomcat异常

1.1 起步内存溢出问题Exception in thread http-bio-8080

1.1.1异常现象

现象如下：
Tomcat7启动后，后台抛出如下异常，前台一直无法登陆

Exception in thread ""http-bio-8080"-exec-6" java.lang.OutOfMemoryError: PermGen space
Exception in thread ""http-bio-8080"-exec-9" java.lang.OutOfMemoryError: PermGen space
Exception in thread "schedulerFactory_Worker-3" java.lang.OutOfMemoryError: PermGen space
Exception in thread ""http-bio-8080"-exec-2" java.lang.OutOfMemoryError: PermGen space
Exception in thread "Timer-0" java.lang.OutOfMemoryError: PermGen space

1.1.2解决方案

给tomcat指定的jdk加大启动的内存参数

-Xms128m -Xmx512m -XX:PermSize=128m -XX:MaxPermSize=128m

1.2 At least one JAR was scanned for TLDs yet contained no TLDs解决办法

在尝试以下操作前，请先关闭杀毒软件，确保不是受杀毒软件的影响；
部署的系统报如下错误，就是百度杀毒引起的。
报错内容：

Jun 03, 2013 1:09:49 PM org.apache.jasper.compiler.TldLocationsCache tldScanJar
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

这样的问题是你的页面中含有的注释，去掉就好了，tomcat7.0.20.

tomcat 7对EL表达式的语法要求比较严格，例如"${owner.new}"因包含关键字new就会导致解析出错。
问题是出来了，怎么解决呢？有三种，如下：

严格遵守java规范，修改对象的属性名称，要求不包含java关键字;
修改EL表达式，例如"${owner.new}"可以修改为"${owner['new']}";
修改tomcat属性，忽略对EL表达式的关键字检查。修改$CATALINA_BASE/conf/catalina.properties文件，添加org.apache.el.parser.SKIP_IDENTIFIER_CHECK=true选项。

1.3 tomcat HTTP Status 405

出现HTTP Status 405 - HTTP method GET is not supported by this URL 原因是：

继承自Httpservlet的Servlet没有重写对于请求和响应的处理方法：doGet或doPost等方法，默认调用父类的doGet或doPost等方法。
父类HttpServlet的doGet或doPost等方法覆盖了你写的到doGet或doPost等方法。

不管是1或2，父类HttpServlet的doGet或doPost等方法默认实现是返回状态码是405的Http错误表示对于指定资源请求方法不被允许。
解决方法：

子类重写doGet或doPost等方法。
在扩张的Servlet中重写doGet或doPost等方法来处理请求和响应时，不要调用父类的doGet或doPost等方法即去掉supper.doGet(request,response)和super.doPost(request,response);

1.4 java.lang.IllegalStateException；Cannot forward after response has been committe

当发生在如下错误的时候，有一个方案可行，
java.lang.IllegalStateException: Cannot forward after response has been committed
当你有多个跳转的页面的语句时候，好好检查一下，当 转发 或者 重定向的时候，需要在后加一个retrun 即可。
服务器中不允许多次跳转，否则会下面这个错误。

因为服务器端使用sendRedirect跳转到客户端的时候,不能在使用req.getRequestDispatcher("跳转的页面").forward(req, reqs);跳转;
所以在跳转之后，return就不会往下执行。

protected void login(HttpServletRequest req, HttpServletResponse reqs) throws ServletException, IOException {  
    // TODO Auto-generated method stub  
    if(req.getUserPrincipal()!=null){  
        String userID = req.getRemoteUser();  
        boolean bol = req.isUserInRole(USER_ROLE_ADMIN);  
        UserModel userModel =connectionDao.getUserModelByUserID(userID);  
        if(bol){  
            req.getSession().setAttribute("user",userModel);  
            reqs.sendRedirect(req.getContextPath()+"/admin/main.jsp");  
            return;  
        }else{  
            reqs.sendRedirect(req.getContextPath()+"/index.jsp");  
            return;  
        }  
    }  
}

1.5 tomcat奇怪错误之A child container failed during start

错误详情：

严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SimpleLogin]]
at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:785)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/SimpleLogin]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
... 7 more
Caused by: java.lang.IllegalArgumentException: Invalid * in servlet mapping
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3217)
at org.apache.catalina.core.StandardContext.addServletMapping(StandardContext.java:3192)
at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1302)
at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1323)
at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:855)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:346)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5173)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
2012-8-23 14:28:31 org.apache.catalina.core.ContainerBase startInternal
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)
at java.util.concurrent.FutureTask.get(Unknown Source)
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.startup.Catalina.start(Catalina.java:675)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:451)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:785)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
2012-8-23 14:28:31 org.apache.catalina.startup.Catalina start
严重: Catalina.start:
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.startup.Catalina.start(Catalina.java:675)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:322)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:451)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
... 11 more
2012-8-23 14:28:31 org.apache.catalina.startup.Catalina start
信息: Server startup in 984 ms

错误原因：
已经发布到tomcat上的某个项目的servlet过滤器配置错误。
如在web.xml下，将过滤规则定为*就是一种错误，需要更正为/*或者其他（但是必须要有/开头，表示当前项目）

posted @ 2022-03-12 13:09 上善若泪阅读(169) 评论(0) 编辑收藏举报

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